Add RTC_ prefix to contructormagic macros.

We must remove dependency on Chromium, i.e. we can't use Chromium's base/logging.h. That means we need to define these macros in WebRTC also when doing Chromium builds. And this causes redefinition.

* DISALLOW_ASSIGN -> RTC_DISALLOW_ASSIGN
* DISALLOW_COPY_AND_ASSIGN -> RTC_DISALLOW_COPY_AND_ASSIGN
* DISALLOW_IMPLICIT_CONSTRUCTORS -> RTC_DISALLOW_IMPLICIT_CONSTRUCTORS

Related CL: https://codereview.webrtc.org/1335923002/

BUG=chromium:468375
NOTRY=true

Review URL: https://codereview.webrtc.org/1345433002

Cr-Commit-Position: refs/heads/master@{#9953}
diff --git a/talk/media/base/videoadapter.h b/talk/media/base/videoadapter.h
index 58d2f03..4c863b3 100644
--- a/talk/media/base/videoadapter.h
+++ b/talk/media/base/videoadapter.h
@@ -92,7 +92,7 @@
   // The critical section to protect the above variables.
   rtc::CriticalSection critical_section_;
 
-  DISALLOW_COPY_AND_ASSIGN(VideoAdapter);
+  RTC_DISALLOW_COPY_AND_ASSIGN(VideoAdapter);
 };
 
 // CoordinatedVideoAdapter adapts the video input to the encoder by coordinating
@@ -201,7 +201,7 @@
   // adaptation is on), but only used if cpu_smoothing_ is set.
   float system_load_average_;
 
-  DISALLOW_COPY_AND_ASSIGN(CoordinatedVideoAdapter);
+  RTC_DISALLOW_COPY_AND_ASSIGN(CoordinatedVideoAdapter);
 };
 
 }  // namespace cricket